Where am I going wrong with this problem? I get the error - TypeError: init() missing 2 required positional arguments: 'm' and 'n'

  class hello:

    def __init__(self, m,n):
      self.g = m
      self.h = n

    def hi(self, x, y):
      a = x   g
      b = x   h
      return a,b
  
  m = 100
  n = 200
  obj = hello()
  c = obj.hi(10,11)
  print(c)

CodePudding user response：

Because you have not provided the positional arguments while constructing your class also there is a bug in the hi function, you have to pass m and n to the hello object when constructing as a positional arguments

class hello:
    def __init__(self, m, n): #this needs m and n
      self.g = m
      self.h = n

    def hi(self, x, y):
      a = x   self.g
      b = x   self.h #use self to access other class members
      return a, b
  
m = 100
n = 200
obj = hello(m, n) #pass m and n to the constructor
c = obj.hi(10, 11)
print(c)

CodePudding user response：

When you are have parameters in your constructor, you cannot initialize an object without passing arguments i.e

class A:
    def __init__(self,a):
        self.a=a

# Creating an instance of the class 
a=A(3)# Here you have to pass the argument as the constructor cannot reference any default value
print(a.a)# 3
# If you don't want to pass any argument you can pass default arguments i.e

class B:
    def __init__(self,b=2)
        self.b=b
# Instantiating class B
b = B() # this will not get any error as it will pick the default value you've provided in the constructor

print(b.b)# 2

# If you want to capture all
class C:
    def __init__(self,a,*args,**kwargs):
        self.a=a
        self.args=args
        self.kwargs=kwargs
# In the C class args will pick all the arguments passed after a is provided and the kwargs will pick the key value pair arguments provided if any